EFFECTS OF APPLICATION RATES OF STEINERNEMA-FELTIAE (NEMATODA, STEINERNEMATIDAE) ON BIOLOGICAL-CONTROL OF THE MUSHROOM FLY LYCORIELLA-AURIPILA (DIPTERA, SCIARIDAE)
Ps. Grewal et Pn. Richardson, EFFECTS OF APPLICATION RATES OF STEINERNEMA-FELTIAE (NEMATODA, STEINERNEMATIDAE) ON BIOLOGICAL-CONTROL OF THE MUSHROOM FLY LYCORIELLA-AURIPILA (DIPTERA, SCIARIDAE), Biocontrol science and technology, 3(1), 1993, pp. 29-40
The potential of Steinernema feltiae for the biological control of Lyc
oriella auripila was tested in commercial mushroom-growing conditions.
The nematodes, applied at rates of 1.5, 3, 6 or 12 x 10(6) infective
juveniles per 34 kg tray of spawn-run compost, were mixed into the cas
ing material before it was spread over the compost surface. When compa
red with untreated control trays, any rate of nematode application sig
nificantly reduced fly emergence. Insecticides significantly reduced m
ushroom yields; nematodes significantly increased them. At a rate of 3
x 10(6) infectives/tray, S. feltiae elicited mean total increases in
the weight and numbers of mushrooms produced of 8% and 11% respectivel
y. The nematodes also reduced the incidence of mushrooms spoiled by tu
nnelling sciarid larvae. The early decline in the numbers of nematodes
persisting in casing was a trend that was reversed later, when eviden
ce was obtained that S. feltiae was recycling in insects that had been
killed. When applied at a rate of 3 - 10(6) infectives/tray of compos
t, S. feltiae should provide reliable and cost-effective biological co
ntrol of L. auripila.